Module sp_io::storage

Interface for accessing the storage from within the runtime.

Structs

• HostFunctions
  Provides implementations for the extern host functions.

Functions

• append
  Append the encoded value to the storage item at key.
• changes_root
  Always returns None. This function exists for compatibility reasons.
• clear
  Clear the storage of the given key and its value.
• clear_prefix
  Clear the storage of each key-value pair where the key starts with the given prefix.
• commit_transaction
  Commit the last transaction started by start_transaction.
• exists
  Check whether the given key exists in storage.
• get
  Returns the data for key in the storage or None if the key can not be found.
• next_key
  Get the next key in storage after the given one in lexicographic order.
• read
  Get key from storage, placing the value into value_out and return the number of bytes that the entry in storage has beyond the offset or None if the storage entry doesn’t exist at all. If value_out length is smaller than the returned length, only value_out length bytes are copied into value_out.
• rollback_transaction
  Rollback the last transaction started by start_transaction.
• root
  “Commit” all existing operations and compute the resulting storage root.
• set
  Set key to value in the storage.
• start_transaction
  Start a new nested transaction.